Snakes are scary enough on land. Some of the world's most venomous snakes, however, live in the water.
The black-banded sea krait can be found in warm waters in the western Pacific Ocean. They are extraordinarily dangerous.
The black-banded sea krait has venom that is ten times deadlier than that of a cobra. Thankfully, they are afraid of people and usually only strike if you antagonize them.